Editing Loon

{{short description|Family of birds}}
{{Other uses}}
{{Use British English|date=June 2014}}
{{Automatic taxobox
| name = Divers/Loons
| fossil_range = [[Early Miocene]] – Recent {{fossilrange|20.43|0}} 
| image = Gavia immer -Minocqua, Wisconsin, USA -swimming-8.jpg
| image_caption = The [[common loon]] (''Gavia immer'')
| parent_authority = [[Elliott Coues|Coues]], 1903<ref>{{cite book|title=Official Lists and Indexes of Names and Works in Zoology|editor=Melville, RV|editor2=Smith, JDD|year=1987|publisher=ICZN|url=https://archive.org/stream/officiallistsind00inte#page/16/mode/1up|page=17}}</ref>
| taxon = Gavia
| authority = [[Johann Reinhold Forster|Forster]], 1788
| type_species = ''[[Gavia immer]]''
| diversity_link = #Systematics and evolution
| diversity = 5 species
| synonyms = Family-level:<br/>
Colymbidae <small>[[Nicholas Aylward Vigors|Vigors]], 1825 (but see [[#Etymology and taxonomy|text]])</small><br/>
Colymbinae <small>[[Charles Lucien Jules Laurent Bonaparte|Bonaparte]], 1831 (but see [[#Etymology and taxonomy|text]])</small><br/>
Urinatores <small>[[Louis Pierre Vieillot|Vieillot]], 1818</small><br/>
Urinatoridae <small>Vieillot, 1818</small>{{Verify source|date=August 2009}}<!-- ICZN (1957-58). Brodkorb (1963) has "[[Robert Ridgway|Ridgway]], 1887". Maybe Ridgway erected family "Urinatoridae" based on Vieillot's "Urinatores" or "Urinatorides". --><br/>
Urinatorides <small>Vieillot, 1818</small>
----
Genus-level:<br/>
''Colymbus'' <small>[[Carl Linnaeus|Linnaeus]], 1758 (but see [[#Etymology and taxonomy|text]])</small><br/>
''Urinator'' <small>[[Bernard Germain Étienne de la Ville, Comte de Lacépède|Lacépède]], 1799</small>
}}

'''Loons''' ([[North American English]]) or '''divers''' ([[British English|British]] / [[Irish English]]) are a group of aquatic [[bird]]s found in much of [[North America]] and northern [[Eurasia]]. All living species of loons are members of the [[genus]] '''''Gavia''''', [[family (biology)|family]] '''Gaviidae''' and [[order (biology)|order]] [[Gaviiformes]].

==Description==
Loons, which are the size of large [[ducks]] or small [[goose|geese]], resemble these birds in shape when swimming. Like ducks and geese, but unlike [[coot]]s (which are [[Rallidae]]) and [[grebe]]s ([[Podicipedidae]]), the loon's toes are connected by [[Bird feet and legs#Webbing and lobation|webbing]]. The loons may be confused with the [[cormorant]]s (Phalacrocoracidae), but can be distinguished from them by their distinct call. Cormorants are not-too-distant relatives of loons, and like them are heavy-set birds whose bellies, unlike those of ducks and geese, are submerged when swimming. Loons in flight resemble plump geese with [[seagull]]s' wings that are relatively small in proportion to their bulky bodies. The bird points its head slightly upwards while swimming, but less so than cormorants. In flight, the head droops more than in similar aquatic birds.

<gallery>
Archibald Thorburn Plate 77.jpg|1918 illustration of a variety of loons by [[Archibald Thorburn]]. Top: [[Common loon]], Mid-left: [[red-throated loon]], Mid-right: [[yellow-billed loon]], Bottom: [[black-throated loon]]
Gavia immer -Marshfield, Vermont, USA -flying-8 (5).jpg|Common loon flying exhibiting the typical flight profile of a ''Gavia'' species
Plongeon imbrin ailes.jpg|[[Common loon]] (''Gavia immer'') rearing up. Note the plump body and pointed but rather short wings
Yellow-billed Loon.jpg|[[Yellow-billed loon]] (''Gavia adamsii'') in winter plumage
</gallery>

Male and female loons have identical [[plumage]], which is largely patterned black-and-white in summer, with grey on the head and neck in some species. All have a white belly. This resembles many [[sea-duck]]s (Merginae) – notably the smaller [[goldeneye (bird)|goldeneye]]s (''Bucephala'') – but is distinct from most cormorants, which rarely have white feathers, and if so, usually as large rounded patches rather than delicate patterns. All species of loons have a spear-shaped bill.

Males are larger on average, but relative size is only apparent when the male and female are together. In winter, plumage is dark grey above, with some indistinct lighter mottling on the wings, and a white chin, throat and underside. The specific species can then be distinguished by certain features, such as the size and colour of the head, neck, back and bill. But reliable identification of loons in winter is often difficult even for experts – particularly as the smaller immature birds look similar to winter-plumage adults, making size an unreliable means of identification.<ref>{{cite journal|author1=Appleby, R.H. |author2=[[Steve Madge|Steve C. Madge]] |author3=[[Killian Mullarney|Mullarney, Killian]] |year=1986|title= Identification of divers in immature and winter plumages|journal=[[British Birds (magazine)|British Birds]]|volume=79|issue=8|pages= 365–91}}
</ref>

Gaviiformes are among the few groups of birds in which the young [[moult]] into a second coat of [[down feather]]s after shedding the first one, rather than growing juvenile feathers with downy tips that wear off, as is typical in many birds. This trait is also found in tubenoses ([[Procellariiformes]]) and [[penguin]]s (Sphenisciformes), both relatives of the loons.<ref name="Olson1985">{{cite book|ref=Olson|author=[[Storrs Olson|Olson, Storrs L.]]|year=1985|chapter-url=http://si-pddr.si.edu/dspace/bitstream/10088/6553/1/VZ_167_Fossil_Record_of_Birds.pdf|chapter=Section X.I. Gaviiformes|editor1=Farner, D.S.|editor2=King, J.R.|editor3=Parkes, Kenneth C.|title=Avian Biology|volume=8|pages=212–14}}</ref>

==Behaviour and ecology==
[[File:Loons Swimming in Wood Lake BC on a Summer Morning.webm|thumb|Loons swimming in Wood Lake, BC on a summer morning]]
Loons are excellent swimmers, using their feet to propel themselves above and under water. However, since their feet are located far back on the body, loons have difficulty walking on land, though they can effectively run short distances to reach water when frightened. Thus, loons avoid coming to land, except for mating and nesting.<ref name="McIntyre1988">{{Cite book |last=McIntyre |first=Judith W. |url=https://archive.org/details/commonloon00judi/ |title=The common loon : spirit of northern lakes |date=1988 |publisher=University of Minnesota Press |isbn=0-8166-1651-5 |edition=2nd |location=Minneapolis |pages=2, 136–139 |oclc=17650487}}</ref> 

Loons fly strongly, though they have high [[wing loading]] (mass to wing area ratio), which complicates takeoff. Indeed, most species must run upwind across the water's surface with wings flapping to generate sufficient lift to take flight.<ref>Evers, David C., James D. Paruk, Judith W. Mcintyre and Jack F. Barr. 2010. Common Loon (Gavia immer), The Birds of North America Online (A. Poole, Ed.). Ithaca: Cornell Lab of Ornithology; Retrieved from the Birds of North America Online: http://bna.birds.cornell.edu/bna/species/313</ref> Only the [[red-throated loon]] (''G. stellata'') can take off from land. Once airborne, loons are capable of long flights during migration. Scientists from the U.S. Geological Survey, who have implanted satellite transmitters in some individuals, have recorded daily flights of up to 1078&nbsp;km in a 24-hour period, which probably resulted from single movements.<ref>{{cite web|url=http://www.umesc.usgs.gov/terrestrial/migratory_birds/loons/questions.html|title=Common Loon Migration Study - Frequently Asked Questions|website=Umesc.usgs.gov|access-date=20 January 2018}}</ref> North European loons migrate primarily via the South Baltic and directly over land to the Black Sea or Mediterranean. Loons can live as long as 30 years and can hold their breath for as long as 90 seconds while underwater.<ref name=Sjolander1972>{{cite journal|author1=Sjölander, S.|author2=Ågren, G.|name-list-style=amp|ref=Sjolander1972|year=1972|title=The reproductive behaviour of the Common Loon|journal=Wilson Bull|volume=84|issue=3|pages=296–308|url=http://sora.unm.edu/node/128875|jstor=4160227}}</ref><ref name=Sjolander1976>{{cite journal|author1=Sjölander, S.|author2=Ågren, G.|name-list-style=amp|ref=Sjolander1976|year=1976|title=The reproductive Behavior of the Yellow-billed Loon, ''Gavia adamsii'' (with G. Ågren)|journal= The Condor|volume=78|pages=454–63|url=http://sora.unm.edu/node/102669|doi=10.2307/1367094|issue=4|jstor=1367094|url-access=subscription}}</ref>

Loons are migratory birds, and in the winter months they move from their northern freshwater lake nesting habitats to southern marine coastlines. They are well-adapted to this change in salinity, however, because they have special salt glands located directly above their eyes. These glands filter out salts in their blood and flush this salty solution out through their nasal passages, which allows them to immediately consume fish from oceans and drink saltwater after their long migration. <ref>{{cite web|url=https://www.nationallooncenter.org/ask-the-scientist/|title=Ask the Scientist|website=National Loon Center Foundation|access-date=11 December 2022}}</ref>

===Diet and feeding===
Loons find their prey by sight. They eat mainly [[fish]], supplemented with [[amphibian]]s, [[crustacean]]s and similar mid-sized aquatic [[fauna]]. Specifically, they have been noted to feed on [[crayfish]], [[frogs]], [[snails]], [[salamanders]] and [[leeches]]. They prefer clear lakes because they can more easily see their prey through the water. The loon uses its pointy bill to stab or grasp prey. They eat [[vertebrate]] prey headfirst to facilitate swallowing, and swallow all their prey whole.

To help digestion, loons swallow small pebbles from the bottoms of lakes. Similar to [[grit (grain)|grit]] eaten by [[chicken]]s, these [[gastrolith]]s may assist the loon's [[gizzard]] in crushing the hard parts of the loon's food such as the [[exoskeleton]]s of crustaceans and the bones of frogs and salamanders. The gastroliths may also be involved in stomach cleaning as an aid to regurgitation of indigestible food parts.

Loons may inadvertently ingest small [[lead]] pellets, released by anglers and hunters, that will contribute to [[lead poisoning]] and the loon's eventual death. Jurisdictions that have banned the use of lead shot and sinkers include but are not limited to [[Maine]], [[New Hampshire]], [[Vermont]], [[Michigan]], some areas of [[Massachusetts]], [[Yellowstone National Park]], [[Canada]], [[Great Britain]], and [[Denmark]].

===Reproduction===
Loons nest during the summer on freshwater lakes and/or large ponds. Smaller bodies of water (up to 0.5&nbsp;km<sup>2</sup>) will usually only have one pair. Larger lakes may have more than one pair, with each pair occupying a bay or section of the lake. The red-throated loon, however, may nest colonially, several pairs close together, in small Arctic [[Tarn (lake)|tarns]] and feed at sea or in larger lakes, ferrying the food in for the young.<ref name=Sjolander1972/><ref name=Sjolander1976/>

Loons mate on land, often on the future nest site, and build their nests close to the water, preferring sites that are completely surrounded by water such as islands or emergent vegetation. Loons use a variety of materials to build their nests including aquatic vegetation, pine needles, leaves, grass, moss and mud. Sometimes, nest material is almost lacking. Both male and female build the nest and incubate jointly for 28 days. If the eggs are lost, the pair may re-nest, usually in a different location. Since the nest is very close to the water, rising water may induce the birds to slowly move the nest upwards, over a metre.<ref name=Sjolander1972/><ref name=Sjolander1976/>

<gallery>
Gavia immer -Osgood Pond, New York, USA -nest-8a.jpg|Common loon on the nest
Juvenile red throated diver.jpg|Juvenile red-throated loon
feedingtime.jpg|Common loon feeding its young
Immature loon with crayfish.jpg|Immature common loon with crayfish
</gallery>

Despite the roughly equal participation of the sexes in nest building and incubation, analysis has shown clearly that males alone select the location of the nest. This pattern has the important consequence that male loons, but not females, establish significant site-familiarity with their territories that allows them to produce more chicks there over time. Sex-biased site-familiarity might explain, in part, why resident males fight so hard to defend their territories.<ref name="Piperetal2008a">{{cite journal|author1=Piper, W.H.|author2=Walcott, C.|author3=Mager, J.N.|author4=Spilker, F.|name-list-style=amp|year=2008|title=Nestsite selection by male loons leads to sex-biased site familiarity|journal=Journal of Animal Ecology|volume=77|issue=2|pages=205–10|doi=10.1111/j.1365-2656.2007.01334.x|pmid=17976165|doi-access=free|bibcode=2008JAnEc..77..205P }}</ref>

Most [[Clutch (eggs)|clutches]] consist of two eggs, which are laid in May or June, depending upon latitude. Loon chicks are [[precocial]], able to swim and dive right away, but will often ride on their parents' back during their first two weeks to rest, conserve heat, and avoid predators. Chicks are fed mainly by their parents for about six weeks but gradually begin to feed themselves over time. By 11 or 12&nbsp;weeks, chicks gather almost all of their own food and have begun to fly.<ref name=Sjolander1972/><ref name=Sjolander1976/> In 2019, a necropsy of a [[bald eagle]] found floating on a Maine lake (beside the floating body of a loon chick) found that the eagle had been stabbed through the heart by an adult loon's beak.<ref>{{cite web |last=D'Auria |first=Danielle |date=2020-05-18 |title=Bald Eagle Shot Through the Heart – By a Loon! |url=https://www.maine.gov/ifw/blogs/mdifw-blog/bald-eagle-shot-through-heart-loon |access-date=2022-06-05 |website=Maine Department of Inland Fisheries & Wildlife}}</ref>

[[Biologist]]s, especially from [[Chapman University]], have extensively studied the mating behaviour of the [[common loon]] (''G. immer''). Contrary to popular belief, pairs seldom [[monogamy|mate for life]]. Indeed, a typical adult loon is likely to have several mates during its lifetime because of territorial takeover. Each breeding pair must frequently defend its territory against "floaters" (territory-less adults) trying to evict at least one owner and seize the breeding site. Territories that have produced chicks in the past year are especially prone to takeovers, because nonbreeding loons use chicks as cues to indicate high-quality territories. One-third of all territorial evictions among males result in the death of the owner; in contrast, female loons usually survive. Birds that are displaced from a territory but survive usually try to re-mate and (re)claim a breeding territory later in life.<ref name="Piperetal2008b">{{cite journal |author1=Piper, W.H. |author2=Walcott, C. |author3=Mager, J.N. |author4=Spilker, F. |name-list-style=amp |year=2008 |title=Fatal Battles in Common Loons: A Preliminary Analysis |journal=Animal Behaviour |volume=75 |issue=3 |pages=1109–15 |doi=10.1016/j.anbehav.2007.10.025 |s2cid=53178013}}</ref><ref name=Piperetal2000>{{cite book |last1=Piper |first1=W. H. |last2=Evers |first2=D. C. |last3=Meyer |first3=M. W. |last4=Tischler |first4=K. B. |last5=Klich |first5=M. |chapter=Do common loons mate for life?: scientific investigation of a widespread myth. |year=2000 |pages=43–49 |editor1-last=McIntyre |editor1-first=J. |editor2-last=Evers |editor2-first=D. C. |title=''Loons: Old History and New Findings.'' |publisher= |location= |isbn=}}</ref><ref>{{cite journal|author1=Piper, W.H.|author2=Tischler, K.B.|author3=Klich, M.|name-list-style=amp|year=2000|journal=Animal Behaviour|volume=59|issue=2|pages=385–94|doi=10.1006/anbe.1999.1295|title= Territory acquisition in loons: The importance of take-over|pmid=10675261|s2cid=23085958}}</ref><ref name=Piperetal2006>{{cite journal|author1=Piper, W.H.|author2=Walcott, C.|author3=Mager, J.N.|author4=Perala, M.|author5=Tischler, K.B.|author6=Harrington, Erin|author7=Turcotte, A.J.|author8=Schwabenlander M.|author9=Banfield, N.|name-list-style=amp|year=2006|title=Prospecting in a Solitary Breeder: Chick Production Elicits Territorial Intrusions in Common Loons|journal=Behavioral Ecology|volume=17|issue=6|pages= 881–888|doi=10.1093/beheco/arl021|doi-access=free}}</ref> 

In 2020, a loon hatched for the first time in over a century in Southeastern Massachusetts at Fall River, the Massachusetts Division of Fisheries and Wildlife and Biodiversity Research Institute. The chicks were relocated in 2015 with the hopes of re-establishing breeding and nesting patterns.<ref>{{Cite web|date=2020-07-10|title=Loon hatches for 1st time in century in southeastern region|url=https://apnews.com/bd5533ca130ecf9bcbca7afb3696c729|access-date=2020-07-10|website=AP NEWS}}</ref>

==Etymology and taxonomy==
{{Listen|filename=loons.ogg|title=Loons calling|pos=left|format=[[Ogg]]}}
The European Anglophone name "diver" comes from the bird's habit of catching fish by swimming calmly along the surface and then abruptly plunging into the water. The North American name "loon" likely comes from either the Old English word ''lumme'', meaning [[:wikt:lummox|lummox]] or awkward person, or the Scandinavian word ''lum'' meaning lame or clumsy. Either way, the name refers to the loon's poor ability to walk on land.<ref>{{Cite book|title=Birds of the World|last=Mobley|first=Jason A.|publisher=Marshall Cavendish|year=2008|isbn=9780761477754|pages=382}}</ref>

Another possible derivation is from the [[Norwegian language|Norwegian]] word ''lom'' for these birds, which comes from [[Old Norse]] '' lómr'', possibly cognate with English "lament", referring to the characteristic plaintive sound of the loon.<ref>{{OEtymD|loon|accessdate=2015-09-04}}</ref> 

The scientific name ''Gavia'' refers to seabirds in general.<ref>[http://www.northland.edu/sigurd-olson-environmental-institute-loon-watch-FAQs.htm LoonWatch – Loon FAQs|Northland College] {{webarchive|url=https://web.archive.org/web/20100813212243/http://www.northland.edu/sigurd-olson-environmental-institute-loon-watch-FAQs.htm|date=2010-08-13|accessdate=2013-04-05}}</ref> The [[scientific name]] ''Gavia'' was the [[Latin]] term for the [[smew]] (''Mergellus albellus''). This small sea-duck is quite unrelated to loons and just happens to be another black-and-white seabird which swims and dives for fish. It is not likely that the [[ancient Romans]] had much knowledge of loons, as these are limited to more northern [[latitude]]s and since the end of the [[last glacial period]] seem to have occurred only as rare winter migrants in the [[Mediterranean]] region.<ref>[[#Brodkorb1963|Brodkorb (1963: pp. 223–24)]]</ref><ref name="Arnott1964">{{cite journal|author=Arnott, W.G.|year=1964|title= Notes on ''Gavia'' and ''Mergvs'' in Latin Authors|journal=Classical Quarterly |series=New Series|volume=14|issue=2|pages=249–62|jstor=637729|doi=10.1017/S0009838800023806|s2cid=170648873 }}</ref>

The term ''gavia'' was transferred from the ducks to the loons only in the 18th century. Earlier [[naturalist]]s referred to the loons as ''mergus'' (the Latin term for diving seabirds of all sorts) or ''colymbus'', which became the genus name used in the first modern scientific description of a ''Gavia'' species (by [[Carl Linnaeus]]) in 1758. Unfortunately, confusion about whether Linnaeus' "[[wastebin genus]]" ''Colymbus'' referred to loons or grebes abounded. North American [[ornithologist]]s used the genus name to refer to grebes, while Europeans used it for loons, following [[Nicholas Aylward Vigors]] and [[Richard Bowdler Sharpe]].

The [[International Commission on Zoological Nomenclature]] tried to settle this issue in 1956 by declaring ''Colymbus'' a suppressed name unfit for further use and establishing ''Gavia'', created by [[Johann Reinhold Forster]] in 1788, as the valid genus name for the loons. However, the situation was not completely resolved even then, and the following year the ICZN had to act again to prevent [[Louis Pierre Vieillot]]'s 1818 almost-forgotten family name Urinatoridae from overruling the much younger Gaviidae. Some eminent ornithologists such as [[Pierce Brodkorb]] tried to keep the debate alive, but the ICZN's solution has been satisfactory.<ref name="Arnott1964"/><ref name="Linnaeus1758">[[Carl Linnaeus|Linnaeus, Carl]] (1758): 68.1. ''Colymbus arcticus. In: [[Systema naturae]] per regna tria naturae, secundum classes, ordines, genera, species, cum characteribus, differentiis, synonymis, locis'' (10th ed., vol. 1): 190 [Latin book]. Lars Salvius, Stockholm ("Holmius"). [http://gdz.sub.uni-goettingen.de/no_cache/dms/load/toc/?IDDOC=265100 Digitized version]</ref><ref name="ICZN">{{cite journal|author=[[International Commission on Zoological Nomenclature]] (ICZN)|year=1957–58|title=The family-group names "Gaviidae" Coues, 1903 and "Urinatoridae" (correction of "Urinatores)" Vieillot, 1818 (Class Aves) – "Opinion" 401 and "Direction" 75|journal=Bulletin of Zoological Nomenclature|volume=15A|pages=147–48|url=https://archive.org/details/bulletinofzoolog15inte}}</ref><ref>[[#Brodkorb1963|Brodkorb (1963: p. 223)]]</ref>

==Systematics and evolution==
All living species are placed in the genus ''Gavia''. It has been suggested that the genus ''Gavia'' originated in Europe during the [[Paleogene]]. The earliest species, ''G. egeriana'', was found in [[early Miocene]] deposits in [[Dolnice]] in the Czech Republic. During the remainder of the [[Miocene]], ''Gavia'' managed to disperse into North America via the [[Atlantic]] coastlines, eventually making their way to the continent's [[Pacific]] coastlines by the [[Late Miocene]].<ref name=M98>{{Cite journal|last1=Mlíkovský|first1=Jiří|year=1998|title=A new loon (Aves: Gaviidae) from the middle Miocene of Austria|url=http://verlag.nhm-wien.ac.at/pdfs/99A_331339_Mlikovsky.pdf|journal=Annalen des Naturhistorischen Museums in Wien, Serie A|pages=331–339}}</ref> Study of the interrelationships of the extant species has found that the red-throated loons are the most basal of the five species.<ref name="Boertmann90">{{cite journal|author=Boertmann, D. |year=1990|title=Phylogeny of the divers, family Gaviidae (Aves)|journal=Steenstrupia |volume=16|pages=21–36}}</ref>
{{Cladogram|caption=Cladogram of the extant ''Gavia'' species.<ref name="Boertmann90" />
|clades=
{{clade
|1={{clade
   |1={{clade
      |1=''Gavia stellata'' }}
|2={{clade
   |1={{clade
      |1=''G. arctica''
      |2=''G. pacifica'' }}
   |2={{clade
      |1=''G. immer''
      |2=''G. adamsii'' }}
}}
}}
}}
}}

{| class="wikitable collapsible"
|-
! Lineage
! Image
! Scientific name
! Distribution
|-
!rowspan="1"  style="text-align:center;"| Basal lineage
|[[File:Red-throated Loon (Gavia stellata) - Summer plumage breeding adult2.jpg|120px]]
|[[Red-throated loon]] or red-throated diver,<br>''Gavia stellata''
|Northern hemisphere generally north of 50°, inland in summer and in coastal areas in winter as far south as Florida and southern China<ref>{{cite iucn|url=https://www.iucnredlist.org/species/22697829/131942584 |title=Red-throated Loon: ''Gavia stellata'' |author=BirdLife International |author-link=BirdLife International |year=2018 |access-date=22 March 2021 |page= e.T22697829A131942584 |doi=10.2305/IUCN.UK.2018-2.RLTS.T22697829A131942584.en}}</ref>
|-
!rowspan="2"  style="text-align:center;"| Black-throated lineage
|[[File:Gavia arctica EM1B1934 (48009481846).jpg|120px]]
|[[Black-throated loon]], Arctic loon, or black-throated diver, <br>''Gavia arctica''
|Northern Europe and Asia, breeding inland and wintering on Atlantic and Pacific coasts<ref>{{cite iucn |author=BirdLife International |date=2018 |title=''Gavia arctica'' |volume=2018 |page=e.T22697834A132606505 |doi=10.2305/IUCN.UK.2018-2.RLTS.T22697834A132606505.en |access-date=13 November 2021}}</ref>
|-
|[[File:PacificLoon24.jpg|120px]]
|[[Pacific loon]] or Pacific diver,  <br>''Gavia pacifica'' (formerly in ''G. arctica'')
|northern Canada and eastern Siberia, and winters along the Pacific coast of North America
|-
!rowspan="2"  style="text-align:center;"| Black-headed lineage
|[[File:Gavia immer (Common Loon) 1APR2017.jpg|120px]]
|[[Common loon]], or great northern diver, <br> ''Gavia immer''
|coasts and lakes of Canada and the US as far south as Mexico, and on the Atlantic coast of Europe
|-
|[[File:Yellow-billed Loon Chipp South 8-12-13 Ryan Askren.jpg|120px]]
| [[Yellow-billed loon]] or white-billed diver, <br>''Gavia adamsii''
| Russia, Canada and the United States, Mexico and Spain.
|-
|}

===Fossil record===
{{Cladogram|caption=Cladogram of the ''Gavia'' species with the inclusion of fossil species.<ref name="Olson&Rasmussen2001">{{Cite journal |last1=Olson |first1=S. L. |last2=Rasmussen |first2= P. C. |year=2001 |title=Miocene and Pliocene birds from the Lee Creek Mine, North Carolina. |journal=Smithsonian Contributions to Paleobiology |volume = 90 |issue = |pages = 233–365|doi=10.5479/si.00810266.90.233 |url=https://www.biodiversitylibrary.org/part/351988 }}</ref>
|clades=
{{clade
|1={{clade
   |1={{clade
      |1=†''Gavia egeriana''
      |2={{clade
         |1=†''G. schultzi''
         |2={{clade
            |1={{clade
               |1=†''G. howardae''
               |2=''G. stellata'' }}
            |2={{clade
               |1=†''G. brodkorbi''
               |2=†''G. paradoxa''
               |3={{clade
                  |1={{clade
                     |1=†''G. moldavica''
                     |2={{clade
                        |1=†''G. concinna''
                        |2={{clade
                           |1=''G. arctica''
                           |2=''G. pacifica'' }} }} }}
                  |2={{clade
                     |1=†''G. fortis''
                     |2={{clade
                        |1=''G. adamsii''
                        |2=''G. immer''}} }} }} }}
}}
}}
}}
}}
}}
}}

Nearly ten prehistoric species have been named to date in the genus ''Gavia'', and about as many undescribed ones await further study. The genus is known from the Early Miocene onwards, and the oldest members are rather small (some are smaller than the [[red-throated loon]]). Throughout the late [[Neogene]], the genus by and large follows [[Cope's Rule]] (that population lineages tend to increase in body size over evolutionary time). [[File:Gavia fossil Vienna.jpg|thumb|Fossil of ''[[Gavia schultzi|G. schultzi]]'' in Vienna]] 

'''List of fossil ''Gavia'' species'''
* †''[[Gavia brodkorbi|G. brodkorbi]]'' <small>Howard, 1978</small> (Late Miocene of Orange County, United States)
* †''G. concinna'' <small>[[Alexander Wetmore|Wetmore]], 1940</small> (Late Miocene/Early Pliocene of west and east United States)
* †''[[Gavia egeriana|G. egeriana]]'' <small>Švec, 1982</small> (Early Miocene of Czechoslovakia ?and Cheswold, Delaware, United States –? Yorktown Early Pliocene of Lee Creek Mine, North Carolina, United States)<ref>A small loon, smaller than ''G. howardae'': [[#Olson|Olson (1985: pp. 213–214)]], [[#Rasmussen|Rasmussen (1998)]], [[#Mlikovsky|Mlíkovský (2002: p. 63)]]</ref>
* †''[[Gavia fortis|G. fortis]]'' <small>[[Storrs Olson|Olson]] & [[Pamela C. Rasmussen|Rasmussen]], 2001</small> (Yorktown Early Pliocene of Lee Creek Mine, North Carolina, United States)<ref name="Olson&Rasmussen2001"/>
* †''[[Gavia howardae|G. howardae]]'' <small>[[Pierce Brodkorb|Brodkorb]], 1953</small> ([[San Diego Formation]], California<ref name="Brodkorb1953">{{Cite journal |last1=Brodkorb |first1=P. |year=1953 |title=A review of the Pliocene loons. |journal=The Condor |volume = 54 |issue = 4 |pages = 211–214|doi=10.2307/1364769 |jstor=1364769 }}</ref> and Yorktown Formation, North Carolina<ref name="Olson&Rasmussen2001"/>
* †''[[Gavia moldavica|G. moldavica]]'' <small>Kessler, 1984</small> (Late Miocene of Chişinău, Moldova)<ref name = milkovsky2002-64>[[#Mlikovsky|Mlíkovský (2002: p. 64)]]</ref>
* †''G. palaeodytes'' <small>Wetmore, 1943</small> (Bone Valley Early/Middle Pliocene of Pierce, Florida, United States)<ref>Known from a few limb bones. Roughly similar in size to [[Pacific loon]], but proportions seem to differ and apparently not close to any living species except maybe [[red-throated loon]]: [[#Brodkorb1953|Brodkorb (1953)]].</ref>
* †''G. paradoxa'' <small>Umanska, 1981</small> (Late Miocene of Čebotarevka, Ukraine)<ref name = milkovsky2002-64/>
* †''[[Gavia schultzi|G. schultzi]]'' <small>Mlíkovský, 1998</small> (Middle Miocene of Sankt Margarethen, Austria)<ref name=M98>{{Cite journal|last1=Mlíkovský|first1=Jiří|year=1998|title=A new loon (Aves: Gaviidae) from the middle Miocene of Austria|url=http://verlag.nhm-wien.ac.at/pdfs/99A_331339_Mlikovsky.pdf|journal=Annalen des Naturhistorischen Museums in Wien, Serie A|pages=331–339}}</ref>

'''List of fossil ''Gavia'' specimens'''
* ''Gavia'' sp. (Early-Middle Miocene of eastern United States)<ref>A tiny loon, smaller and more delicate than even the [[sympatric]] contemporary ''G. egeriana''-like birds. Probably a distinct species – [[sexual dimorphism]] in loons is not very pronounced: [[#Rasmussen|Rasmussen (1998)]].</ref>
* ''Gavia'' sp. (Calvert Middle Miocene ?or Pleistocene of Maryland, United States) – same as ''Gavia'' cf. ''immer'' below?<ref>[[USNM]] 16612, [[Anatomical terms of location#Proximal and distal|distal]] right [[tibiotarsus]]. Smaller than [[common loon]]; the polished-bone look and large size of the specimen makes a Miocene origin rather unlikely: Wetmore (1941), [[#Olson|Olson (1985: p. 214)]].</ref>
* ''Gavia'' spp. (Middle Miocene of Steinheim, Germany) – three species<ref name = milkovsky2002-64/>
* ''Gavia'' sp. (Early Pliocene of Empoli, Italy)<ref>Known from a skull very similar to the [[black-throated loon]]. Initially assigned to ''G. concinna'', but this is not very likely: [[#Mlikovsky|Mlíkovský (2002: p. 64)]], and see also at ''"Gavia" portisi''.</ref>
* ''Gavia'' sp. (Early Pliocene of Kerč Peninsula, Ukraine)<ref name=milkovsky2002-64/>
* ''Gavia'' cf. ''concinna'' (San Diego Middle/Late<ref name=":0">{{Cite web|url=https://sora.unm.edu/sites/default/files/journals/condor/v055n04/p0211-p0214.pdf|title=A REVIEW OF THE PLIOCENE LOONS|last=BRODKORB|first=PIERCE|date=July 1953|website=Searchable Ornothological Research Archive}}</ref><!-- only Late? --> Pliocene of San Diego, California, United States) – two species?<ref>Initially in part (specimens [[LACM]] 2110, 2142) assigned to ''G. concinna'', but apparently one or two undescribed smaller species, about the size of the [[Pacific loon]]: [[#Brodkorb1953|Brodkorb (1953)]], [[#Mlikovsky|Mlíkovský (2002: p. 64)]].</ref>
* ''Gavia'' sp. (Early Pleistocene of Kairy, Ukraine)<ref name=milkovsky2002-64/>
* ''Gavia'' cf. ''immer'' (Pleistocene of California and Florida, United States) – possibly a ''G. immer'' [[paleosubspecies]]<ref name=b53>[[#Brodkorb1953|Brodkorb (1953)]]</ref>

''"Gavia" portisi'' from the [[Late Pliocene]] of [[Orciano Pisano]], [[Italy]], is known from a [[cervical vertebra]] that may or may not have been from a loon. If so, it was from a bird slightly smaller than the [[common loon]]. Older authors were quite sure the bone was indeed from a ''Gavia'' and even considered ''G. concinna'' a possibly [[junior synonym]] of it. This is now regarded as rather unlikely due to the quite distinct range and age. The [[Early Pliocene]] ''Gavia'' skull from [[Empoli]] (Italy) was referred to ''G. concinna'', and thus could conceivably have been of ''"G." portisi'' if that was indeed a loon. The [[holotype]] vertebra may now be lost, which would make ''"G." portisi'' a ''[[nomen dubium]]''.<ref name=b53/><ref>[[#Brodkorb1963|Brodkorb (1963: p. 224)]], [[#Mlikovsky|Mlíkovský (2002: pp. 64, 256–57)]]</ref>

==In popular culture==
*Various Indigenous myths from the [[California]] region have a recurring figure, Loon or Loon Woman, based on the [[common loon#Relationship with humans|common loon]].<ref>{{cite journal|author=Demetracopoulou, D.|jstor=535774|doi=10.2307/535774|title=The Loon Woman Myth: A Study in Synthesis|journal=The Journal of American Folklore|volume=46|issue=180 |year=1933|pages=101–128}}</ref>
*The [[Tlingit]] of [[Alaska]] believe that loon cries forecast rain. [[Silver Bay (Alaska)|Gaǥeit]] is named after the common loon (''kagit'').<ref>{{cite book |page=191 |editor1-last=Tidemann |editor1-first=Sonia |editor2-last=Gosler |editor2-first=Andrew |title=Ethno-ornithology: Birds, Indigenous Peoples, Culture and Society |date=2010 |publisher=Earthscan |location=London |isbn=978-1-84407-783-0}}</ref>

*The [[common loon]] is the provincial bird of [[Ontario]] and is depicted on the Canadian one-dollar coin, which has come to be known affectionately as the "[[loonie]]".<ref>Stewart, Barry D. (2004): ''Across The Land: A Canadian Journey Of Discovery''. Trafford Publishing. {{ISBN|1-4120-2276-2}}, p. 143</ref>
*The common loon is the official state bird of [[Minnesota]].<ref>Heinrichs, Ann (2003): ''Minnesota''. Compass Point Books. {{ISBN|0-7565-0315-9}}, p. 44</ref>
*[[Mercer, Wisconsin]], promotes itself as the "Loon Capital of the World".<ref>Moran, Mark; Sceurman, Mark; Godfrey, Linda S. & Hendricks, Richard D. (2005): ''Weird Wisconsin: Your Travel Guide to Wisconsin's Local Legends and Best Kept Secrets''. Sterling Publishing. {{ISBN|0-7607-5944-8}}, p. 78</ref>
*[[Henry David Thoreau]] describes a playful and inspiring acquaintance with a loon on [[Walden Pond]] in his book ''[[Walden]]''.<ref>chapter "Brute Neighbors"</ref>
*The [[Great Lakes Loons]] are a minor-league professional baseball team based in [[Midland, Michigan]], United States. The primary mascot is Lou E. Loon.<ref>{{cite news |last=Gonzalez |first=John |date=August 11, 2013 |title=Experience Michigan: The Great Lakes Loons fans go bonkers for mascots Rall E. Camel and Lou E. Loon! |url=http://www.mlive.com/entertainment/index.ssf/2013/08/experience_michigan_the_great.html |publisher=[[Booth Newspapers]] |access-date=August 1, 2017}}</ref>
*The [[Warner Bros. Animation|Warner Bros.]]/[[Amblin Entertainment|Amblin]] cartoon [[Tiny Toon Adventures]] features Shirley the Loon, who speaks with a thick Valley girl accent and is obsessed with superficial New Age paraphernalia. She is voiced by [[Saturday Night Live]] cast member [[Gail Matthius]].<ref>{{Citation|title=Tiny Toon Adventures (TV Series 1990â€"1995)|url=http://www.imdb.com/title/tt0098929/fullcredits|access-date=2019-01-29}}</ref>
*The [[Major League Soccer]] club [[Minnesota United FC]] use a loon in the club's crest, and as a nickname for the team.<ref>{{cite news |last=La Vaque |first=David |date=October 27, 2016 |title=Minnesota United to donate portion of 2017 season ticket purchases to help loons |url=http://www.startribune.com/minnesota-united-to-donate-portion-of-2017-season-ticket-purchases-to-help-loons/398911731/ |work=[[Star-Tribune]] |location=Minneapolis |access-date=August 1, 2017}}</ref>
*Thanks to its inclusion as a preset in the [[E-mu Emulator]], a specific sample of a Canadian loon, notably heard in "[[Sueño Latino]]" (1989) and in [[808 State]]’s "[[Pacific State (song)|Pacific State]]" (1989), has become a recurring motif in electronic-based popular music.<ref>{{cite web|url=https://pitchfork.com/thepitch/474-anaconda-pacific-state-sueno-latino-and-the-story-of-a-sample-that-keeps-coming-back/|title="Anaconda", "Pacific State", "Sueño Latino", and the Story of a Sample That Keeps Coming Back|website=Pitchfork|author=Philip Shurburne|date=8 September 2014}}</ref><ref>{{cite web|url=https://www.soundonsound.com/people/classic-tracks-808-state-pacific-state|title=Classic Tracks: 808 State 'Pacific State' 
|website=Soundonsound.com|access-date=20 January 2018}}</ref>

==References==
{{Reflist}}

==Bibliography==
*{{cite journal|ref=Brodkorb1953|author=[[Pierce Brodkorb|Brodkorb, Pierce]]|year=1953|title=A Review of the Pliocene Loons|journal=[[Condor (journal)|Condor]]|volume=55|issue=4|pages=211–14|url=http://sora.unm.edu/sites/default/files/journals/condor/v055n04/p0211-p0214.pdf|doi= 10.2307/1364769|jstor=1364769}}
*{{cite journal|ref=Brodkorb1963|author=[[Pierce Brodkorb|Brodkorb, Pierce]]|year=1963|title=Catalogue of fossil birds. Part 1 (Archaeopterygiformes through Ardeiformes)|journal=Bulletin of the Florida State Museum, Biological Sciences|volume=7|issue=4|pages=179–293|url=http://fulltext10.fcla.edu/cgi/t/text/text-idx?c=feol&idno=UF00001514&format=pdf}}
* {{cite journal|ref=Mayr2004|author=Mayr, Gerald|year=2004|title=A partial skeleton of a new fossil loon (Aves, Gaviiformes) from the early Oligocene of Germany with preserved stomach content|journal=[[Journal of Ornithology|J. Ornithol.]]|volume=145|pages=281–86|doi=10.1007/s10336-004-0050-9|url=http://www.senckenberg.de/files/content/forschung/abteilung/terrzool/ornithologie/colymboides.pdf|issue=4|bibcode=2004JOrn..145..281M |s2cid=1070943|access-date=2006-09-20|archive-url=https://web.archive.org/web/20150924100426/http://www.senckenberg.de/files/content/forschung/abteilung/terrzool/ornithologie/colymboides.pdf|archive-date=2015-09-24|url-status=dead}}
* {{cite book|ref=Mayr2009|author=Mayr, Gerald|year=2009|title=Paleogene Fossil Birds|publisher=Springer-Verlag|place=Heidelberg/New York|isbn=978-3-540-89627-2}}
* {{cite book|ref=Mlikovsky|author=Mlíkovský, Jirí|year=2002|url=http://www.nm.cz/download/JML-18-2002-CBE.pdf|title=Cenozoic Birds of the World, Part 1: Europe|publisher=Ninox Press|place=Prague}}<!-- This should be treated with extreme caution as regards merging of species. Splits are usually good though. See also critical review in Auk121:623-627 here http://www.findarticles.com/p/articles/mi_qa3793/is_200404/ai_n9396879 -->
* Montana Fish, Wildlife & Parks (Montana FW&P) (2007): [https://web.archive.org/web/20090206134020/http://fwp.mt.gov/fieldguide/detail_ABNBA01030.aspx Animal Field Guide: Common Loon]; retrieved 2007-05-12.
* {{cite book|ref=Olson|author=[[Storrs Olson|Olson, Storrs L.]]|year=1985|chapter-url=http://si-pddr.si.edu/dspace/bitstream/10088/6553/1/VZ_167_Fossil_Record_of_Birds.pdf|chapter=Section X.I. Gaviiformes|editor1=Farner, D.S.|editor2=King, J.R.|editor3=Parkes, Kenneth C.|title=Avian Biology|volume=8|pages=212–14}}
* {{cite journal|ref=Rasmussen|author=[[Pamela C. Rasmussen|Rasmussen, Pamela C.]]|year=1998|title=Early Miocene Avifauna from the Pollack Farm Site, Delaware|journal=Delaware Geological Survey Special Publication|volume=21|pages=149–51|url=http://www.deldot.gov/archaeology/pollack/pdf/fossil_site/pollack_144-146.pdf|access-date=2013-09-30|archive-date=2015-09-23|archive-url=https://web.archive.org/web/20150923213717/http://www.deldot.gov/archaeology/pollack/pdf/fossil_site/pollack_144-146.pdf|url-status=dead}}
*{{Cite thesis |last=Sprengelmeyer |first=Quentin D |title=A PHYLOGENETIC REEVALUATION OF THE GENUS GAVIA (AVES: GAVIIFORMES) USING NEXT-GENERATION SEQUENCING |date=April 2014 |publisher=Northern Michigan University |url=https://commons.nmu.edu/cgi/viewcontent.cgi?article=1017&context=theses}}
*{{cite journal|author= [[Robert W. Storer|Storer, Robert W.]] |year=1956|title= The Fossil Loon, ''Colymboides minutus''|journal=[[Condor (journal)|Condor]]|volume=58|issue=6|pages= 413–426|url=http://sora.unm.edu/sites/default/files/journals/condor/v058n06/p0413-p0426.pdf|doi=10.2307/1365096|jstor=1365096}}
* {{cite journal|author=[[Alexander Wetmore|Wetmore, Alexander]]|year=1941|title=An Unknown Loon from the Miocene Fossil Beds of Maryland|journal=[[Auk (journal)|Auk]]|volume=58|issue=4|pages=567|url=http://sora.unm.edu/sites/default/files/journals/auk/v058n04/p0567-p0567.pdf|doi=10.2307/4078641|jstor=4078641}}
* [[United States Fish and Wildlife Service]] (USFWS) (2005): [https://web.archive.org/web/20070711002115/http://www.fws.gov/midwest/seney/documents/Loonupdatejun05.pdf Common Loons at Seney NWR (June 2005)], fws.gov; accessed July 6, 2017.

===Recordings===
*''Voices of the Loon'', [[Robert J. Lurtsema]], narrator. recorded by William E. Barklow. North American Loon Fund/[[National Audubon Society]]. (1980)

==External links==
{{Wiktionary|loon}}
{{Commons category|Gavia}}
{{Wikispecies|Gaviidae}}
* [http://www.tolweb.org/Gaviidae/26386 Tree of Life Gaviidae]
* [https://web.archive.org/web/20150318044737/http://www.learner.org/jnorth/tm/loon/identification.html Loon sounds]
* [http://ibc.lynxeds.com/family/divers-gaviidae Loon videos] {{Webarchive|url=https://web.archive.org/web/20110903205845/http://ibc.lynxeds.com/family/divers-gaviidae |date=2011-09-03 }} on the Internet Bird Collection
* [http://loonproject.org/ The Loon Project website]
* [http://www.loon.org/ Loon Preservation Committee]
* [http://digitalcommons.unl.edu/bioscidivingbirds/ ''Diving Birds of North America''] by [[Paul Johnsgard]]
* [http://www.nfb.ca/film/loon_dreaming/ ''Loon Dreaming''] - an animated short from the [[National Film Board of Canada]]

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{{Birds}}
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[[Category:Articles containing video clips]]
[[Category:Extant Eocene first appearances]]
[[Category:Gaviiformes| ]]
[[Category:Priabonian first appearances]]
[[Category:Taxa named by Johann Reinhold Forster]]
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